Hydrogen bond-assisted 1,2-cis O-glycosylation under mild hydrogenolytic conditions

A hydrogen bond-assisted alpha-selective glycosylation reaction by using 4,6-dibenzyloxy-1,3,5-triazin-2-yl (DBT) ,B-glycosyl donors was developed for the efficient construction of 1,2-cis -alpha-glycosidic bond in nat-ural products. This method was applied successfully to the direct synthesis of complex oligosaccharide-derived glycolipids with simple protecting chemistry. Mechanistic studies using the NMR spectroscopy and DFT calculation provide a proof of concept for hydrogen bond-assisted glycosylation reaction towards alpha-specific construction of O-glycosidic linkage.(c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.